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s390/maccess: fix absolute lowcore virtual vs physical address confusion

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Due to historical reasons memcpy_absolute() and friend functions
misuse the notion of physical vs virtual addresses difference.

Note: this does not fix a bug currently, since virtual and physical
addresses are identical.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Alexander Gordeev 2022-01-21 10:44:25 +01:00 committed by Vasily Gorbik
parent 98c0d24d1e
commit 1f231e2950
1 changed files with 9 additions and 8 deletions
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17
arch/s390/mm/maccess.c
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@ -199,15 +199,15 @@ out:
/*
* Check if physical address is within prefix or zero page
*/
static int is_swapped(unsigned long addr)
static int is_swapped(phys_addr_t addr)
{
unsigned long lc;
phys_addr_t lc;
int cpu;
if (addr < sizeof(struct lowcore))
return 1;
for_each_online_cpu(cpu) {
lc = (unsigned long) lowcore_ptr[cpu];
lc = virt_to_phys(lowcore_ptr[cpu]);
if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc)
continue;
return 1;
@ -223,7 +223,8 @@ static int is_swapped(unsigned long addr)
*/
void *xlate_dev_mem_ptr(phys_addr_t addr)
{
void *bounce = (void *) addr;
void *ptr = phys_to_virt(addr);
void *bounce = ptr;
unsigned long size;
cpus_read_lock();
@ -232,7 +233,7 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
size = PAGE_SIZE - (addr & ~PAGE_MASK);
bounce = (void *) __get_free_page(GFP_ATOMIC);
if (bounce)
memcpy_absolute(bounce, (void *) addr, size);
memcpy_absolute(bounce, ptr, size);
}
preempt_enable();
cpus_read_unlock();
@ -242,8 +243,8 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
/*
* Free converted buffer for /dev/mem access (if necessary)
*/
void unxlate_dev_mem_ptr(phys_addr_t addr, void *buf)
void unxlate_dev_mem_ptr(phys_addr_t addr, void *ptr)
{
if ((void *) addr != buf)
free_page((unsigned long) buf);
if (addr != virt_to_phys(ptr))
free_page((unsigned long)ptr);
}